Day trading is buying and selling stocks or stock options throughout the day, these trades can be a few seconds to a few hours long. Typically, day traders do not hold a trade overnight and try to sell their positions before the close of the trading day.
There are a ton of strategies for day trading and what one person trades on their phone another person uses 3 screens and has bloomberg on the tv to watch the news. None of them are wrong and in my experience traders should play to their gifts and if you're good at making trades on a set of lines or with a certain strategy, why fight it? Everyone's brain and experiences are different so what I see, you may not and the reverse is true. If you can trade with a good win rate on price action, why weigh yourself down with more charts and analytics?
There is more risk associated with day trading, but there is also more potential reward. Someone holding a long position may hope to get 10% over the next 6 months or the year, a day trader hopes to get that 10% in a few minutes, but understand there is more loss potential.
Only trade with what you can afford to lose
There is always risk when you enter the stock market and day trading is no different. You should always only trade with what you can afford to lose.
Tossing your grocery money in on a yolo may sound ok at first and you'll sell before it gets too low, but then you don't and you're eating ramen. It happens. Margin calls, explanations to your partner about where the money went. Avoid it. Just don't. or do but know the risks.
With a good math based strategy and strict discipline, it is possible to make huge profits day trading, but it isn't easy and it doesn't usually happen overnight.